1. Field of the Invention
This invention relates to dual dispense containers comprised of an outer container and an inner container for separately packaging two products and dispensing them as one stream from the dual dispense container orifice. More particularly, this invention is directed to a dual dispense container whose orifice is generally configured as a cloverleaf.
2. Description of Related Art
Dual dispense containers are known. They are used to package products that are intended to be kept separate in the package and not brought into contact or mixed until after they are dispensed from the orifice of the tube. Examples of such containers are collapsible dual dispense tubes. Examples of such products are dentifrices comprised of two products that have different colors and are to be dispensed with a striped appearance, and dentifrices comprised of a peroxide gel product and sodium bicarbonate paste product that chemically react with each other and are to be mixed after dispensing.
Products packaged in a dual dispense containers are intended to be dispensed in a desired ratio for better appearance in the case of striped products, and for maximum effect upon mixing and/or during use, in the case of reactive products. For the latter, it is usually desired that there be as much inter-product surface contact area as possible upon dispensing to maximize mixing during use.
Heretofore, dual dispense containers with an inner tube neck and body disposed within an outer tube neck and body, have not been suitable for dispensing two products having similar flow characteristics in the same or substantially the same volumes, i.e., in substantially a 1:1 dispense ratio. The problem has been that the inner tube dispense orifice for one product and the outer tube dispense orifice for the other product have had different dispense areas and flow resistances, and the flow channels for the passage of the products through the necks to their orifices have had different product flow surface contact areas and flow resistances. Thus, the two products with similar flow characteristics experience different pressure drops as they flow to and are dispensed from the dual dispense orifice. Accordingly, the products are dispensed in different volumes.
Prior dual dispense containers may be rendered generally suitable for dispensing products with dissimilar flow characteristics at times in substantially equal volumes by properly matching the respective products and their dissimilar flow characteristics with the dissimilar flow resistances of the respective inner and outer containers' flow channels and orifices. Usually, the product with the higher viscosity (thicker, less free-flowing) is packaged in the container having the flow path and orifice with relatively less surface contact area and less flow resistance, and the product with the lower viscosity is packaged in the container with relatively more surface contact area and flow resistance. Typically, the higher viscosity product has been contained in the inner tube because it has a more direct path and less flow resistance to the inner tube orifice, and the lower viscosity product has been contained in the outer tube because it has a tortuous path to and greater flow resistance to the outer tube orifice.
Examples of these prior dual dispense containers are disclosed in U.S. Pat. No. 2,939,610 to Castelli et al, and No. 1,699,532 to Hopkins. The Castelli et al patent discloses, in FIGS. 1-8, a collapsible dual dispense tube having a side-by-side dispense orifice. The inner tube neck and orifice are D-shaped and the arcuate surface of the neck engages the annular outer tube neck. The orifice for the product contained in the inner tube is within the "D" of the neck and is smaller than the orifice for the product contained in the outer tube. The product with the higher viscosity is contained in the inner tube and the product with the lower viscosity is contained in the outer tube. Because the D-shaped inner tube neck engages more than half of the outer tube bore, most of the product in the outer tube must undergo significantly greater flow resistance because it must travel a circuitous path from one side of the tube to the other to exit from only one side of the dual tube orifice. Thus, this tube would not be suitable for dispensing products with the same or similar flow characteristics in equal or substantially equal volumes. The D-shaped side-by-side orifice provides a dispense stream with product-to-product contact along one surface, and thus provides minimal opportunity for product mixing. The Castelli et al patent also discloses, in FIGS. 9 and 10, a collapsible dual dispense tube having what is sometimes referred to as a sandwich-type orifice, formed by an annular outer tube throat that engages the end walls of a rectangular inner tube orifice and neck. The sandwich orifice has two opposed, small hemi-spherical outer tube orifice sections, one to either side of a large rectangular inner tube orifice. Although this dual tube sandwich orifice and neck design is an improvement over the D-shaped design because it provides two opposed orifices for the outer tube product, the design still provides significantly greater surface area and flow resistance for the lower viscosity outer tube product than for the inner tube product. Much of the outer tube product must still follow a circuitous flow path to be dispensed from the two opposed outer tube orifices. Thus, this dual dispense tube orifice and neck also is not suitable for dispensing products with the same or similar flow properties in the same or substantially the same volumes. Also, it provides a dispensed stream with product mixing along two surfaces for interproduct mixing.
The Hopkins patent discloses, in FIGS. 9 and 10, a collapsible dual dispense tube having a sandwich-shaped orifice that provides more dispense area for the outer tube product than the sandwich orifice of the Castelli et al patent. The Hopkins patent also discloses, in FIGS. 7 and 8, a collapsible dispensing tube formed by an annular outer tube throat that engages the end walls of a triangular inner tube orifice. This dual dispense tube orifice and neck would not be suitable for dispensing products with similar flow properties in equal or substantially equal volumes because the flow paths and orifices for the respective products do not provide the same or substantially the same product contact surface area or flow resistances. It is believed that the direct and wide flow path for the inner tube product to and through its wide, open-centered triangular orifice has less flow resistance and pressure drop than the path for the outer tube product to and through its segmented orifice. The triangular-shaped dual dispense orifice provides product-to-product contact along three arcuate surfaces for enhanced dispensed product mixing.
It has been found that the problem with prior collapsible dispensing tubes in not being able to dispense paired products with similar flow characteristics in the same or substantially the same volumes has been that the flow path and orifice for the higher viscosity inner tube product have not provided sufficient product flow surface contact area, and hence flow resistance and pressure drop, to be equal or substantially equal to the flow resistance and pressure drop provided by the flow path and orifice for the lower viscosity outer tube product.
It has been found that for the foregoing reason, collapsible dual dispense tubes having D-shaped and sandwich shaped flow paths and orifices with dissimilar flow resistances have been unable to initially dispense products with the same or similar flow characteristics in the same or substantially the same volumes. Such dual dispense tubes have not provided sufficient flow restriction, especially as to the inner tube flow path and orifice for the higher viscosity product, to generate enough pressure drop to initially dispense the products in the same or substantially the same volumes. D-shaped and sandwich shaped orifice dual dispense tubes have also been found to be problematical in that even if, after initial dispense, they commence dispensing in equal or substantially equal volumes, the dispense ratio typically is not maintained over a substantial duration, say from one-half to two-thirds, of the dispense life of the dual dispense tube. The dispense ratio tends to vary significantly over the dispense life of the tube. One reason for this is that with repeated non-uniform squeezings at different locations on the outer tube body wall, and with the consequent contortions of the outer tube body wall, the distribution of product in the outer tube becomes less uniform. This, and the tortuous path that much of the outer tube product must follow to reach the outer tube orifice(s), causes variations in the amount of outer tube product available for dispensing and dispensed. This in turn causes variations in the product dispense ratio which increase over the dispense life of the dual tube. Typically, relatively less outer tube product is dispensed with each squeezing, and eventually more or only inner tube product is dispensed.
It has been found that the solution to the above-mentioned inability of prior dual dispense containers, e.g., collapsible dual dispense tubes, to dispense two products of the same or similar flow characteristics in the same or substantially the same volumes is to employ a dual tube orifice and/or neck design, preferably a dual tube orifice and neck design, that provides more surface contact area and more flow resistance for the internal higher viscosity product, preferably while providing more orifice sections for more direct flow and higher volume dispensing of the lower viscosity outer tube product, to thereby equalize or substantially equalize the flow resistances and therefore the flow and dispense volumes of the inner and outer tube products. The solution is met by providing a dual dispense tube having a dual dispense orifice and preferably also an inner tube neck design that generally corresponds to or is shaped like a cruciform or cloverleaf.
In view of the above, it is an object of this invention to provide an improved dual dispense container that overcomes shortcomings of conventional, including side-by-side and sandwich orifice, dual dispense containers.
It is therefore an object of this invention to provide an improved dual dispense container that is suitable for separately packaging two products having the same or similar flow characteristics, and for simultaneously dispensing the products in the same or substantially the same volumes.
Another object of this invention is to provide an improved dual dispense container that provides the same or similar flow resistance for each of its products in their paths to and through the dual dispense orifice.
It is another object of this invention to provide an improved dual dispense container having an orifice that generally corresponds to a cloverleaf.
It is another object of this invention to provide an improved dual dispense container having an inner tube neck and orifice disposed within a outer tube neck and orifice, wherein the inner tube neck in horizontal cross-section generally corresponds to a cloverleaf.
It is yet another object of this invention to provide an improved dual dispense container that is adapted to equalize product dispense pressure requirements for simultaneously dispensing two products having the same or similar flow characteristics in the same or substantially the same volumes.
It is yet another object of this invention to provide an improved dual dispense container that reduces dual product dispense ratio variation during the dispensing life of the container.
It is yet another object of this invention to provide an improved dual dispense container that simultaneously dispenses its products in substantially the same volumes over a substantial portion of the product dispensing life of the container.
It is still another object of this invention to provide an improved dual dispense container adapted to dispense a stream of products having increased interproduct surface contact area and hence increased interproduct mixability.